Reconstructing and predicting the near-Earth radiation environment utilising dimension reduction
Energetic particles in near-Earth space can pose serious risks to satellites and humans in space. During geomagnetic storms, radiation levels can rise sharply, and many satellite anomalies have been linked to such events. Understanding the global evolution of particle radiation environment is challenging because each satellite measures conditions only at a single location. Further, they have different instrumental error and often vary by orders of magnitude. This makes it difficult to reconstruct how particle populations such as in the radiation belts and in the ring current evolve in space and time.
In the previous funding period, our work focused on developing data assimilation methods for the most energetic electrons in the radiation belts, which can cause deep dielectric charging in satellites. In the current funding period, we will shift our focus to the ring current, another important population of energetic particles. The ring current can charge satellite surfaces, degrade solar panels and even influence power grids on Earth.
Data assimilation for the ring current is more complex than for the radiation belts. The ring current varies with local time and requires a four-dimensional description, and its evolution follows more complex physical equations. It also changes more rapidly and shows finer spatial structures, making its behavior more difficult to interpret.
To overcome these challenges, we will develop new data assimilation methods tailored to the ring current. We will investigate advanced techniques such as the Ensemble Kalman Filter to estimate unknown physical parameters and to directly assimilate particle fluxes into our models. These new methods will be tested within the CRC and applied to multi-dimensional diffusion and diffusion–convection systems relevant to space physics.
Project duration: 07/2021 – 06/2029
Funding: German Research Foundation (DFG)
Project Website: www.sfb1294.de
Principal Investigators: Prof. Dr. Yuri Shprits (GFZ), Prof. Dr. Melina Freitag (University of Potsdam)
Collaboration: University of Potsdam